Texture-based colour correction

Abstract

A method for correcting a colour image, wherein the image being represented by a plurality of colour values, the method comprising the steps of: determining local texture features of the image based on the colour values; and correcting the colour values based on the local texture features.

1 . A method for correcting a colour image, wherein said image being represented by a plurality of image data with colour values, the method comprising the steps of: 
 determining local texture features of the image data of the image based on colour values; of the image data and correcting the colour values based on the local texture features.    
     
     
         2 . The method according to  claim 1 , wherein the colour values being respectively represented by a set of element values, each element value belonging to a colour channel; and, 
 in the correcting step: 
 the element values of the same colour channel are corrected in the same way; and/or the local texture features are determined based on the element values of different channels.  
   
     
     
         3 . The method according to  claim 1 , wherein, in said correcting step: 
 the colour values or the element values and the local texture features which relate to the same location are combined for performing the correction.    
     
     
         4 . The method according to  claim 3 , 
 wherein local information on critical scene content is provided and/or the image is analysed whether one or more regions represent a critical scene content, for instance a memory colour; and    wherein the combination of the colour values or element values and local texture features locally depends on the local information and/or the results of the analysis.    
     
     
         5 . The method as claimed in  claim 1 , wherein 
 the texture features represent measures for the texture at locations in the image and, in said correcting step, the colour balance is corrected with respect to a target colour balance; wherein 
 those colour values at locations with high measures of texture have a higher influence on the correction with respect to the target colour balance than colour values at locations with low measures of texture; and/or  
 those colour values at locations with low measures of texture have a higher influence on a change of the target colour balance performed before the correction than colour values at locations with high measures of texture.  
   
     
     
         6 . The method according to  claim 1 , wherein, in said correcting step: 
 channel characteristics for the respective colour channels are determined based on the element values of the respective colour channel and the local textures, and the element values of the respective colour channel are corrected based on the channel characteristic of the respective colour channel and based on at least one predetermined reference relationship among the channel characteristics.    
     
     
         7 . A Computer program which, when loaded in a computer or when running on a computer causes the computer to perform the steps of  claim 1 .  
     
     
         8 . A computer program storage medium comprising the computer program of  claim 7 , and/or signal wave carrying information corresponding to the computer program of  claim 7 .  
     
     
         9 . Apparatus for adjusting the colour balance comprising a image data processing device for performing the method steps as claimed in  claim 1 .  
     
     
         10 . A colour printer, a photographic laboratory, or a digital video or still camera comprising the apparatus of  claim 9  or the program of  claim 7.